1. Field of the Invention
This invention relates to chairs and seats of the type having the means to alter their contours for the pleasure of one using them. More particularly, this invention relates to methods and apparatus for causing a chair or seat to massage the back or legs of one sitting in them.
2. Description of the Related Art
Discomfort, pain, injuries and diseases involving the back are common. The back consists of a column of bones called vertebrae, which are separated by discs that act as cushions and are held together by muscles and ligaments. A normal healthy back has three natural curves, the upper cervical curve, the thoracic curve and the lower lumbar curve. When these three curves are in normal alignment, a person's body weight is evenly distributed throughout the vertebrae and discs, and when the muscle groups of the back are strong and flexible the person may move freely and without effort. Natural aging, premature aging, misuse, or injury, give rise to certain spinal problems which cause a variety of symptoms, such as stiffness, pain, tingling and numbness. More serious back problems may require corrective surgery, but the majority of back problems respond favorably to non-surgical therapy. Many back problems may be healed by a combination of rest, modalities, medication, or bracing.
Many types of apparatus and methods have heretofore been proposed and developed for alleviating back problems. Because the average person spends a great deal of time sitting, considerable effort has been directed to the design of chairs and seats so as to alleviate any back discomfort that an individual might experience as a result of an extended period of sitting.
Inflatable air bladders have been used in a variety of configurations to provide adjustments to the contour of a seat, and in this manner to enhance the comfort of the individual using the seat. For example, see U.S. Pat. Nos. 3,326,601, 4,707,027, 4,833,614, 5,135,282, 5,558,398, 5,658,050, 5,967,608 and 6,098,000.
Because of the popularity of therapeutic (i.e., having the power to provide comfort from muscular aches and pains) massages for relieving the discomfort from a wide assortment of ailments, it is probably not surprising that many types of massagers, utilizing cyclicable inflatable bladders, have been built into various types of seating. For example, see U.S. Pat. Nos. 3,760,801, 4,175,297, 4,524,762, 4,634,179, 5,211,162 and 5,848,982.
Since “continuous passive motion (CPM)” applied to an injured limb (i.e., repetitiously moving the limb through a range of positions as medically prescribed) has for some time been a common method of rehabilitative treatment, it is probably also not surprising that continuous passive motion devices, also utilizing cyclicable inflatable bladders, have been introduced into chairs and seats. For example, see U.S. Pat. Nos. 4,981,131, 4,986,260, 5,529,573, 5,624,383, 5,637,076 and U.S. Pat. Application Publication No. 2002/0,091,345.
It is notable that CPM devices are distinguished in the patent literature from massagers for their claimed ability to “treat or prevent low back pain” as compared with massagers which are identified as providing “superficial stimulation of the soft tissue.” This distinction is said to be attributable to the differences between the amplitudes and frequencies of spinal motions caused by the respective devices. CPM devices are said to provide cyclic spinal mobilization (flexing between adjacent vertebrae sufficient to alter the vertebral discs . . . i.e., to cause lordotic movement), which is reportedly quite different from any “massage effect.” The preferred cycle times for CPM devices are noted to be “too slow for any massage effect to occur.”
The degree of lordotic movement is said to depend upon the individual person's lumbar compliance, which varies within the population. “Experience has shown that for persons having normal lumbar compliance, displacements on the order of at least about one inch and as much as three inches or more, delivered over a total cycle duration of twenty to thirty seconds (including both inflation and deflation intervals) generally can provide sufficient spinal mobilization to give a beneficial effect . . . Generally a total cycle duration that is too short (on the order, for example, of about five seconds or less) does not permit the spine to respond passively to effect a spinal mobilization, and can be distracting to the user, while a total cycle duration that is too long (on the order, for example, of ten minutes) can result in static conditions between successive inflations and deflations, reducing the effectiveness of the spinal movements.” See col. 8, lines 7-24 of U.S. Pat. No. 4,981,131.
More recent inventive contributions in this area have focused on the control systems for such massagers and CPM devices. These have included systems that employ transducers for measuring the forces exerted by the inflated bladders, that control the voltage supply to the electric pumps as a means of regulating the rates at which they inflate any bladders, and that prolong the operating life of the pumps used in these applications. See U.S. Pat. Nos. 5,624,383, 5,637,076 and U.S. Patent Application Publication No. 2002/0,091,345.
In general, FIGS. 1 and 2 from U.S. Pat. No. 4,707,027 display the basic elements of such massagers and CPM devices. These are seen to consist of one or more inflatable bladders, an electric pump and various control valves and conduits which serve to inflate and deflate the bladders. Meanwhile, FIG. 3 from U.S. Pat. No. 4,981,131 displays a typical control system for such massagers and CPM devices. It consists of a timer and timer operated valves that regulate the fluid flow from the pump to the bladders; alternately, certain pumps are available which permit the user to directly set their power levels and their intervals of operation.
Despite much prior art, there still exists a need for further technological improvements in this area. For example, simpler systems are needed which provide lower cost, longer life and more reliable, problem-free operation, plus provide more comfort and enjoyment for those using them. Among some of the problems being experienced by the current apparatus in this area include: excessive pump and air flow noise during their operation, excessive heat buildup in the seat materials surrounding such apparatus, and excessive manpower hours needed to assemble and install the various elements of such apparatus. Additionally, greater pleasure from their use is thought to be available as a result of continued development in the orientation and means of operation for the inflatable bladders of such devices.
3. OBJECTS AND ADVANTAGES
There has been summarized above, rather broadly, the prior art that is related to the present invention in order that the context of the present invention may be better understood and appreciated. In this regard, it is instructive to also consider the objects and advantages of the present invention.
It is an object of the present invention to provide a therapeutic seat massager that is not afflicted with the current, major operational problems of such apparatus, including: excessive pump and air flow noise, excessive heat buildup in the adjoining seat materials, and excessive manpower hours needed to assemble and install such apparatus.
It is another object of the present invention to provide a simpler, therapeutic seat massager having a longer operational life than current models.
It is yet another object of the present invention to provide a therapeutic seat massager which has a greater variety of massaging capabilities than current models.
It is still object of the present invention to provide a therapeutic seat massager which is in the form of a completely assembled package which can easily and quickly be installed into an existing seat.
It is an object of the present invention to provide a lower cost therapeutic seat massager that can be offered as a low cost, seat option on a wide range of automobiles.
These and other objects and advantages of the present invention will become readily apparent as the invention is better understood by reference to the accompanying summary, drawings and the detailed description that follows.